- Servo-Quality Proportional Valves
Also called high-performace proportional valves. These are more common. Make sure the valve has a ±10V command signal (not 4-20mA).
- Servo Valves (current driven)
Flapper-nozzle, or jet pipe. Often called just servo valves, these require a current input, such as ±50mA. To use these with an RMC, a Current-to-Voltage converter is required, such as the VC2124.
Servo-Quality Proportional Valves
For great performance, trouble-free set-up and machine operation (this means lower startup and maintenance costs), Delta recommends using linear valves with a zero-lapped spool and on-board electronics.
The RMC75E and RMC150E do support non-linear valves (with a single "knee"), but it requires extra set up. A linear valve is the easiest to use.
This means the flow vs command signal profile is linear (at least up to about 8 volts):
Terms such as "kink", "knee", and "progressive" indicate a non-linear valve.
This means the spool is cut so that as soon as a voltage is applied to the valve, hydraulic fluid starts flowing.
This means you don't need to wory about a separate card, and typically, with a good valve, you don't need to make any adjustments on the electronics.
If you enjoy headaches, choose a valve with an overlapped spool (we call that deadband), and a non-linear flow versus command signal profile. Notice, however, that headaches can result in costs savings. Especially for OEM applications, where you just need to go through the difficulty once, and then pump out volume, it can be well worth it to get a valve that is barely good enough to do the job. On single applications, the time savings in setup usually justify a good valve.
Recommended Servo-Quality Proportional Valves
Here are some valves that Delta knows have been used successfully. Many valves offer +/-10V or 4-20mA input. Make sure to choose +/-10V.
4WRREH: Size NG6. Very fast response. Make sure to choose the ±10V command option.
4WRPEH: Sizes NG6 and 10. The NG6 is not as fast as the 4WRREH, but still good. Make sure to choose the ±10V command option.
4WRLE: Sizes 10-35. Make sure to get the V spool with the L (linear) flow characteristic.
D1FP: Size NG6. Make sure to choose the ±10V command option.
D3FP: Size NG10. Make sure to choose the ±10V command option.
The D1FH is not as high performance as the D1FP, but will also work quite well.
DLHZO-TEB and DLKZOR-TEB: single-stage, sizes NG6 and 10. The first L in the part numbers indicates a sleeve, which gives more precise control and faster response.
DPZO-LEB: two-stage, sizes 10-35
The BE indicates the Basic Integral digital driver, which is all that is necessary when using the RMC to control the valve.
D661: Very fast response and high flow.
D681-D685: Very fast response and high flow.
79-series: Crazy high response for 200 gpm (750 lpm)!
Axis Pro valve are very high response. D03 and D05. Choose level 1 in order to work with the RMC. Make sure to choose the ±10V command option.
The LSVG-01-EH and The LSVG-03-EH are crazy high response and linear with on-board electronics. D03 and D05, but maxes out at 60 lpm. Make sure to choose the ±10V command option. Yuken also makes a similar high response D05 valve, the SE1024, with more flow, 130 L/min.
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